These values are definitely off. It’s probably the way your meter measures DC and AC components of a signal, rather than something fundamentally wrong with the PSU. It would be good to put a scope across each of these capacitors to see exactly what the PSU is producing, but I suppose you don’t have one! Where are you located?

Regarding the DC volts, I’d expect that the DC voltage at the top of C36 would be higher than that at C37, which would then be higher than that at C38. Otherwise, where does the additional DC come from?

Regarding the AC ripple voltages, I’d be horrified if the ripple at the top of C37 was any more than a volt or so. Millivolts would be more likely. Your AC voltages make no sense at all.

It looks from the schematic that all three capacitors are in the same housing. There should be four terminals: the three positive capacitors and the fourth negative common, which looks as though it might be connected to an outer can – but maybe not: it may not be a can at all, but an insulating sleeve.

So you would measure the voltages from each individual capacitor connection to the common terminal.

Ok if chassis ground is the common terminal that is how I measured them. The capacitor has 3 inner terminals in the center and 3 locking rings on the outside and the can was attached to chassis. I assumed that the three looking rings were common.

Actually, looking at my (pretty blurry) copy of the schematic, I see that C38 doesn’t appear to be part of the PSU supply chain, but is simply a smoothing capacitor for the two screen grids in the RF and converter stages. Nevertheless the voltages you quoted are definitely wrong, especially the AC measurements.

But if you look at the schematic you’ll see that the chassis is not connected to DC ground – the DC ground , which you need to connect the -ve meter probe to, is indicated by a “comb” icon, and the chassis is indicated by an upside-down Xmas tree icon. The most easily identified point in the DC ground line is probably the battery negative terminal, which should have a yellow wire. At least, it was yellow in 1948! 🙂

If you make these voltage measurements again, using that point as the negative, you’ll probably get much more sensible values.

Cookie and Privacy Settings

How we use cookies

We may request cookies to be set on your device. We use cookies to let us know when you visit our websites, how you interact with us, to enrich your user experience, and to customize your relationship with our website.

Click on the different category headings to find out more. You can also change some of your preferences. Note that blocking some types of cookies may impact your experience on our websites and the services we are able to offer.

Essential Website Cookies

These cookies are strictly necessary to provide you with services available through our website and to use some of its features.

Because these cookies are strictly necessary to deliver the website, refuseing them will have impact how our site functions. You always can block or delete cookies by changing your browser settings and force blocking all cookies on this website. But this will always prompt you to accept/refuse cookies when revisiting our site.

We fully respect if you want to refuse cookies but to avoid asking you again and again kindly allow us to store a cookie for that. You are free to opt out any time or opt in for other cookies to get a better experience. If you refuse cookies we will remove all set cookies in our domain.

We provide you with a list of stored cookies on your computer in our domain so you can check what we stored. Due to security reasons we are not able to show or modify cookies from other domains. You can check these in your browser security settings.

Check to enable permanent hiding of message bar and refuse all cookies if you do not opt in. We need 2 cookies to store this setting. Otherwise you will be prompted again when opening a new browser window or new a tab.

Click to enable/disable essential site cookies.

Google Analytics Cookies

These cookies collect information that is used either in aggregate form to help us understand how our website is being used or how effective our marketing campaigns are, or to help us customize our website and application for you in order to enhance your experience.

If you do not want that we track your visit to our site you can disable tracking in your browser here:

Click to enable/disable Google Analytics tracking.

Other external services

We also use different external services like Google Webfonts, Google Maps, and external Video providers. Since these providers may collect personal data like your IP address we allow you to block them here. Please be aware that this might heavily reduce the functionality and appearance of our site. Changes will take effect once you reload the page.

Google Webfont Settings:

Click to enable/disable Google Webfonts.

Google Map Settings:

Click to enable/disable Google Maps.

Google reCaptcha Settings:

Click to enable/disable Google reCaptcha.

Vimeo and Youtube video embeds:

Click to enable/disable video embeds.

Other cookies

The following cookies are also needed - You can choose if you want to allow them: